1. Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method and apparatus for performing cooperative multiple point transmission and reception (hereinafter referred to as CoMP) in a multi-cell wireless communication system.
2. Related Art
In wireless communication systems, research is recently being done on schemes for improving the performance of a user equipment (hereinafter referred to as UE) placed at the boundaries of a cell. For example, in a wireless communication system having a multi-cell structure, active research is being done on a CoMP technique in which signals are transmitted through inter-cell cooperation. In accordance with the CoMP technique, a UE (in particular, a UE placed at the boundaries of a cell) can have an improved transmission power gain and an improved signal sensitivity through communication with a number of base stations.
The UE placed at the boundaries of the cell does not receive signals from only a serving cell providing services. That is, the UE also receives signals from neighbor cells adjacent to the serving cell (the neighbor cells are hereinafter referred to as interfering cells). A UE within a serving cell may receive a signal which is transmitted from an interfering cell to a UE within the interfering cell. In this case, the signal received from the interfering cell may function as interference with the UE within the serving cell.
In the case in which the number of transmission antennas of a transmitter is one or more, it has been known that a dirty paper coding (DPC) scheme supports a maximum information transmission rate. There is a signal transmission and reception scheme in which in the case in which an interference signal in addition to a noise signal exists in a channel between a transmitter and a receiver, if the transmitter previously knows the interference signal, the receiver is not influenced by the interference signal. An example of the signal transmission and reception scheme is the DPC scheme.
However, the conventional DPC scheme is based on the assumption that a transmitter previously knows an interference signal. As described above, in the CoMP technique, the signals of neighbor cells function as interference signals. Accordingly, to apply the DPC scheme to the CoMP technique, a serving cell and neighbor cells (i.e., interfering cells) must share their data which are transmitted to respective UEs within the cells. To share the data between the cells as described above, a large amount of information needs to be exchanged between the cells, leading to high feedback overhead.
Accordingly, there is a need for a method and apparatus which is capable of performing a CoMP technique using a DPC scheme without sharing data between cells.